GetConnectables performance optimization

network-store-iidm-impl/src/main/java/com/powsybl/network/store/iidm/impl/NetworkImpl.java

@@ -771,7 +771,51 @@ public <C extends Connectable> Iterable<C> getConnectables(Class<C> clazz) {
 
     @Override
     public <C extends Connectable> Stream<C> getConnectableStream(Class<C> clazz) {
-        return index.getIdentifiables().stream().filter(clazz::isInstance).map(clazz::cast);
+        Objects.requireNonNull(clazz);
+        if (clazz == BusbarSection.class) {
+            return getBusbarSectionStream().map(c -> (C) c);
+        } else if (clazz == Generator.class) {
+            return getGeneratorStream().map(c -> (C) c);
+        } else if (clazz == Line.class) {
+            return getLineStream().map(c -> (C) c);
+        } else if (clazz == TwoWindingsTransformer.class) {
+            return getTwoWindingsTransformerStream().map(c -> (C) c);
+        } else if (clazz == ThreeWindingsTransformer.class) {
+            return getThreeWindingsTransformerStream().map(c -> (C) c);
+        } else if (clazz == Battery.class) {
+            return getBatteryStream().map(c -> (C) c);
+        } else if (clazz == DanglingLine.class) {
+            return getDanglingLineStream().map(c -> (C) c);
+        } else if (clazz == LccConverterStation.class) {
+            return getLccConverterStationStream().map(c -> (C) c);
+        } else if (clazz == VscConverterStation.class) {
+            return getVscConverterStationStream().map(c -> (C) c);
+        } else if (clazz == Load.class) {
+            return getLoadStream().map(c -> (C) c);
+        } else if (clazz == ShuntCompensator.class) {
+            return getShuntCompensatorStream().map(c -> (C) c);
+        } else if (clazz == StaticVarCompensator.class) {
+            return getStaticVarCompensatorStream().map(c -> (C) c);
+        } else {
+            Stream<C> s = Stream.empty();
+            for (Class<?> connectableClass : List.of(BusbarSection.class,
+                                                     Generator.class,
+                                                     Line.class,
+                                                     TwoWindingsTransformer.class,
+                                                     ThreeWindingsTransformer.class,
+                                                     Battery.class,
+                                                     DanglingLine.class,
+                                                     LccConverterStation.class,
+                                                     VscConverterStation.class,
+                                                     Load.class,
+                                                     ShuntCompensator.class,
+                                                     StaticVarCompensator.class)) {
+                if (clazz.isAssignableFrom(connectableClass)) {
+                    s = Stream.concat(s, getConnectableStream((Class<C>) connectableClass));
+                }
+            }
+            return s;
+        }
     }
 
     @Override

network-store-iidm-impl/src/test/java/com/powsybl/network/store/iidm/impl/GetConnectablesTest.java

@@ -0,0 +1,39 @@
+/**
+ * Copyright (c) 2023, RTE (http://www.rte-france.com)
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+package com.powsybl.network.store.iidm.impl;
+
+import com.powsybl.iidm.network.*;
+import com.powsybl.iidm.network.test.EurostagTutorialExample1Factory;
+import org.junit.Test;
+
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author Geoffroy Jamgotchian <geoffroy.jamgotchian at rte-france.com>
+ */
+public class GetConnectablesTest {
+
+    @Test
+    public void test() {
+        Network network = EurostagTutorialExample1Factory.create();
+        List<Generator> generators = network.getConnectableStream(Generator.class).toList();
+        assertEquals(1, generators.size());
+        List<Line> lines = network.getConnectableStream(Line.class).toList();
+        assertEquals(2, lines.size());
+        List<TwoWindingsTransformer> transformers = network.getConnectableStream(TwoWindingsTransformer.class).toList();
+        assertEquals(2, transformers.size());
+        List<Load> loads = network.getConnectableStream(Load.class).toList();
+        assertEquals(1, loads.size());
+        List<Injection> injections = network.getConnectableStream(Injection.class).toList();
+        assertEquals(2, injections.size());
+        List<HvdcConverterStation> converterStations = network.getConnectableStream(HvdcConverterStation.class).toList();
+        assertTrue(converterStations.isEmpty());
+    }
+}